Directional microporous diffuser and directional sparging

ABSTRACT

A method for treating contaminates includes emitting plural streams of a fluid into a soil formation with the streams having different radii of influences in different directions. A direction microporous diffuser includes a holder member having plural compartments and plural hollow, elongated members having porous sidewalls, the plural hollow, elongated members supported in the plural compartments of the holder member with each hollow, elongated member including a an inlet port at a first end of the elongated member and second end of the elongated member being sealed.

BACKGROUND

There is a well-recognized need to clean-up contaminants found in groundwater, i.e., aquifers and surrounding soil formations. Such aquifers andsurrounding soil formations may be contaminated with variousconstituents including organic compounds such as, volatile hydrocarbons,including chlorinated hydrocarbons such as dichloroethene (DCE),trichloroethene (TCE), and tetrachloroethene (PCE). Other contaminatesthat can be present include vinyl chloride, 1,1,1 trichloroethane (TCA),dichloroethane (DCA), 1,4 dioxane, and very soluble gasoline additivessuch as methyl tertiary butyl ether (MTBE). Other contaminants may alsobe encountered.

SUMMARY

Often such contaminants are found in areas that are inaccessible, e.g.under parking lots, road beds buildings, airport runways, high-usehighways, and the like where sparging techniques that require drillingof wells or driving of microporous diffusers directly into soils, closeto or underneath such road beds, parking lots, buildings and the likemay be impractical because of the large number of penetrations throughreinforced concrete or surfaces sensitive to loading or proximity toheavily traveled or used area.

According to an aspect of this invention, a method includes deliveringplural streams of a fluid to plural inlets of a diffuser comprised ofplural hollow elongated members each having porous sidewalls andemitting at least one stream of the fluid into a soil formation throughat least one of the plural hollow, elongated members.

Other aspects of the invention include that the inlets are coupled toone end of the plural hollow members with opposing ends of the membersbeing sealed. The method includes sequencing fluids to the inlets toprovide the plural streams in different sequences. The method includescontrolling a solenoid controlled, multi-port valve to sequencing fluidsto the inlets to provide the plural streams in different sequences. Thediffuser is a microporous diffuser and includes a holder membersupporting the plural hollow, elongated members in plural compartmentsof the holder member. The elongated members are comprised of wellscreen. The method includes emitting microbubbles having a bubble sizeof less than 200 microns. The method includes driving the diffuser intothe ground. The method includes disposing the diffuser in a well. Thediffuser emits microbubbles having a size in a range of 1 to 200microns. The diffuser is comprised of 10 slot well-screen. The diffuseris comprised of a mesh having a mesh size in a range of 40 to 200 mesh.

According to a further aspect of the invention, an apparatus includes aplurality of directional diffusers arranged in a spaced arrangement totreat a site, a trunk line that delivers a fluid to the plurality ofdirectional diffusers, a plurality of multi-port distribution valves inproximity to inlet ports of the directional diffusers; and for each ofthe multi-port distribution values and a plurality of feed lines coupledfrom the multi-port distribution value to inlets on the directionaldiffusers.

Other aspects of the invention include an ozone generator coupled to thetrunk line and wherein the first fluid comprises ozone. The apparatusincludes an air compressor coupled to the trunk line and an ozonegenerator coupled to the trunk line and wherein the first fluidcomprises air-ozone. At least one of the directional diffusers has aninlet for receiving a flow of a second fluid. At least one of thedirectional diffusers includes an inlet for receiving a flow of a secondfluid, that is surrounded by a plurality of inlets that receive flows ofthe first fluid. The diffuser is 10 slot well-screen and the apparatusincludes a source of air-ozone as the first fluid and a source of aperoxide as the second fluid. The directional diffusers are microporousdirectional diffusers and the apparatus includes a source of air-ozoneas the first fluid and a source of a peroxide as the second fluid. Thedirectional diffuser includes a pointed member disposed on a portion ofthe directional diffuser to allow the directional diffuser to be driveninto the ground. The directional diffuser is microporous having a poresize in a range of 0.1 to 200 microns. The directional diffuser iscomprised of a mesh having a mesh size of at least 40 mesh. Thedirectional diffuser is comprised of a mesh having a mesh size in arange of 40 to 200 mesh.

According to a still further aspect of the invention, an apparatusincludes a holder member having plural compartments, plural hollow,elongated members having porous sidewalls, the plural hollow, elongatedmembers supported in the plural compartments of the holder member witheach hollow, elongated member including, an inlet port at a first end ofthe elongated member with the second end of the elongated member beingsealed.

Other aspects of the invention include the holder member is elongated,with sidewalls of the plural hollow, elongated members having a porositycharacteristic of 10 slot well-screen or less. Sidewalls of the pluralelongated members have a porosity characteristic of less than 200microns. The plural hollow, elongated members are cylinders. The plural,hollow elongated members are comprised of a metal or a plastic. Theplural, hollow elongated members are comprised of a plastic that is ahydrophobic material. The plural, hollow elongated members are comprisedof sintered, fused microscopic particles of plastic. The compartmentshave walls that have a curvature that corresponds to a curvature of theplural, hollow elongated members. The apparatus includes at least oneband that is disposed about the plural members to hold the pluralmembers in the compartments of the holder member. The compartments arearranged in quadrants. The holder member has a borehole through a lengthof the holder member. The apparatus includes an inlet attached to theholder member to feed fluid into the borehole in the holder member.

According to an aspect of this invention, a microporous diffuserincludes a holder member having plural compartments, each compartmenthaving a generally partially circular sidewall, plural hollow,cylindrical tubes having porous sidewalls, the plural hollow,cylindrical tubes supported in the plural compartments of the holdermember with each hollow, cylindrical tube including, an inlet port at afirst end of the cylindrical tubes with a second end of the cylindricaltube being sealed.

Other aspects of the invention include the holder member being elongatedand with the cylindrical tubes having a porosity characteristic of 10slot well-screen or less. The microporous diffuser has sidewalls of thecylindrical tubes have a porosity characteristic of less than 200microns. The cylindrical tubes are comprised of a metal or a plastic.The microporous diffuser includes at least one member disposed to holdthe plural cylindrical tubes in the compartments of the holder member.The compartments are arranged in quadrants and wherein there are fourcylindrical tubes.

One or more advantages can be provided from the above. While, anon-directional microporous diffuser can enlarge its radius of influence(ROI) by placing the non-directional microporous diffuser deeper withinan aquifer, e.g., a substantial distance below the contaminants, thedirectional microporous diffuser provides a mechanism that can dischargemicrobubbles over a broad lateral area while having directionalmicroporous diffuser remain close to contaminated groundwater zonesduring sparging.

The directional microporous diffuser can cover broad lateral areaswithout diluting its effectiveness, since the oxidant gas emitted fromthe directional microporous diffuser can be emitted close to the sourceof contamination. It is possible that the effective radius of influencecan be expanded, at least two-fold, without increasing the flow, bysequentially directing fluid from portions of the directional diffuser.

The lateral areas over which the microbubbles are emitted can be largersince all of the microbubbles emitted from the directional microporousdiffuser can be directed into one area at a time.

The provision of multiple cylindrical members that are independently feda fluid stream and independently controlled permits microbubbles toemerge from the directional microporous diffuser in accordance withwhich of the inlet ports of the directional microporous diffuserreceives the fluid stream from the outlet ports of thesolenoid-controlled valve. The directional microporous diffuser togetherwith the solenoid valve permits a gas stream from the central feed to bedirected through one, two, three or all four of the quadrants of thedirectional microporous diffuser. In general, using a single quadrant ata time permits the microbubbles to exit the directional microporousdiffuser and provide a generally elliptical shaped zone of influence inthe surrounding soil formation. The zone of influence will extendfurther in a direction perpendicular from the directional microporousdiffuser than tangentially from the sidewalls of the directionalmicroporous diffuser

The solenoid-controlled valve can be controlled to rotate the pattern ofmicrobubbles emitted from the directional microporous diffuser. Thus,microbubbles exit from only a first quadrant during a first time period,then only from a second quadrant during a second time period, and soforth. The control can be automated or manual. The directionalmicroporous diffuser allows fewer wells and sparging arrangements to beconstructed on a site for a given sparging arrangement capacity, sinceall of the capacity of the pumps and so forth can be directed into asingle portion, e.g., quadrant of a microporous diffuser at any onetime.

The details of one or more embodiments of the invention are set forth inthe accompanying drawings and the description below. Other features,objects, and advantages of the invention will be apparent from thedescription and drawings, and from the claims.

DESCRIPTION OF DRAWINGS

FIGS. 1A and 1B are cross-sectional views showing sparging treatmentexamples.

FIG. 2 is a diagrammatical view showing a multi-sparging apparatusinstallation.

FIGS. 3A-3E are diagrams depicting details of a directional diffuser inthe example shown in FIG. 1A or 1B.

FIGS. 4A-4C are diagrams of solenoid controlled valves.

FIGS. 5A-5D are diagrams depicting details of a directional diffuser inthe example shown in FIG. 1A or 2B.

FIGS. 6A and 6B are cross-sectional view of sidewalls of the directionaldiffusers of FIGS. 3A-3 c, 5A-5C and 7A-7C showing exemplaryconstruction details.

FIGS. 7A-7C are diagrams depicting details of a directional diffuser inthe example shown in FIG. 1A or 2B.

FIG. 8 is a cross-sectional view showing an alternative spargingtreatment example.

FIGS. 9A-9C are alternative configurations of the diffuser depicted inFIGS. 5A-5D or 7A-7C.

DETAILED DESCRIPTION

Referring now to FIG. 1A, a sparging arrangement 10 for treating plumes,sources, deposits or occurrences of contaminants, is shown. Thearrangement 10 is disposed in a well 12 that has a casing 14 with screen14 a. The casing 14 supports the ground about the well 12. Disposedthrough the casing 14 are one or more directional microporous diffusers50, 70 (discussed in FIGS. 3A-3C or 4A-4C).

The arrangement 10 also includes a first air compressor/pump 22 and acompressor/pump control mechanism 27 to feed a first fluid, e.g., airinto a two port mixing valve 23 and a second pump 26 and coupled to asecond source, e.g., an ozone generator 28 to feed ozone (O₃) to themixing valve 23. Other arrangements are possible.

The mixing valve 23 is coupled via a check valve 25 to an inlet port ofa solenoid-controlled valve 30. Solenoid-controlled valve 30, as shownin FIG. 4, has a common inlet port 31 and here four branch or outletports 32 a-32 d. A control arrangement 35 controls thesolenoid-controlled valve 30. The control arrangement 35 can be a seriesof switches to actuate the solenoids, via lines 35 a, or could be morecomplicated schemes. The gas mixture from the central mixing valve 23 isdistributable to each of the outlet ports 32 a-32 d of thesolenoid-controlled valve 30.

In some embodiments, packing material, e.g., sand may be disposed aroundthe directional microporous diffuser 50, 70.

A conventional microporous diffuser can enlarge its radius of influence(ROI) by placing the microporous diffuser deeper within an aquifer,e.g., a substantial distance below the contaminants. However, thisapproach dilutes the effectiveness of such a microporous diffuser sincethe oxidant gas emitted from the conventional microporous diffusertravels vertically for some distance in order to reach the contaminants.Along the way some of the oxidant can dissolve, is absorbed or otherwisebecomes ineffective. The directional microporous diffuser 50, 70provides a mechanism that can cover broad lateral areas while stayingclose to contaminated groundwater zones.

Referring now to FIG. 1B, an alternative sparging arrangement 100 fortreating plumes, sources, deposits or occurrences of contaminants, isshown. The arrangement 100 includes one or more directional microporousdiffusers 50, 70 (discussed in FIGS. 3A-3C and 4A-4C, respectively)disposed directly through a surrounding ground/aquifer region 16. Asshown in FIG. 1B, the directional microporous diffusers 50, 70 are of atype that has a pointed member 51 on an end thereof to allow the pointedmember to be driven or injected into the ground without the need for awell or casing as in FIG. 1A.

The arrangement 100 also includes the first air compressor/pump 22, thecompressor/pump control mechanism 27, two port mixing valve 23, thesecond pump 26, ozone generator 28 and so forth as discussed above. Themixing valve 23 is coupled via a check valve 25 to an inlet port of asolenoid-controlled valve 30 controller via the control arrangement 35,as also discussed above.

In either arrangement 10 or 100, the outlet ports of thesolenoid-controlled valve 30 are controlled by solenoids thatselectively open and close the outlet ports 32 a-32 d permitting fluidto escape from one or more of the outlet ports 32 a-32 d. The outletports 32 a-32 d are coupled to feed lines generally 33 that are coupledto inlet fittings on a cap of the directional microporous diffuser 50,70. The directional microporous diffuser 50, 70 allows microbubbles tobe directed in selected directions into a surrounding soil formation 16,as discussed below.

In the embodiment described, a gas stream of ozone and air is deliveredto the directional microporous diffuser 50, 70. Other fluid streamscould be used including, air, air enhanced with oxygen, a gas andliquid, e.g., hydrogen peroxide, air/ozone enhanced with hydrogenperoxide, or a hydro peroxide and so forth.

In the illustrated embodiment, microbubbles of air and ozone exit fromwalls of the directional microporous diffuser 50, 70. The microbubblesof air/ozone affect substantial removal of below-mentioned or similartypes of contaminants. The arrangement 10 can also include a pump (notshown) that supplies nutrients such as catalyst agents including ironcontaining compounds such as iron silicates or palladium containingcompounds such as palladized carbon. In addition, other materials suchas platinum may also be used.

The microbubbles promote rapid gas/gas/water reactions with volatileorganic compounds in which a substrate (catalyst or enhancer)participates in, instead of solely enhancing, dissolved (aqueous)disassociation and reactions. The production of microbubbles andselection of appropriate size distribution is provided by usingmicroporous material and a bubble chamber for optimizing gaseousexchange through high surface area to volume ratio and long residencetime within the liquid to be treated. The equipment promotes thecontinuous production of microbubbles while minimizing coalescing oradhesion.

The injected air/ozone combination moves as a fluid into the material tobe treated. The use of microencapsulated ozone enhances and promotesin-situ stripping of volatile organics and simultaneously terminates thenormal reversible Henry's Law reaction. The process involves promotingsimultaneous volatile organic compounds (VOC) in-situ stripping andgaseous decomposition, with moisture (water) and substrate (catalyst orenhancer). The basic chemical reaction mechanism of air/ozoneencapsulated in micron-sized bubbles is further described in several ofmy issued patents such as U.S. Pat. No. 6,596,161 “Laminated microporousdiffuser”; U.S. Pat. No. 6,582,611 “Groundwater and subsurfaceremediation”; U.S. Pat. No. 6,436,285 “Laminated microporous diffuser”;U.S. Pat. No. 6,312,605 “Gas-gas-water treatment for groundwater andsoil remediation”; and U.S. Pat. No. 5,855,775, “Microporous diffusionapparatus” all of which are incorporated herein by reference.

The compounds commonly treated are HVOCs (halogenated volatile organiccompounds), PCE, TCE, DCE, vinyl chloride (VC), EDB, petroleumcompounds, aromatic ring compounds like benzene derivatives (benzene,toluene, ethylbenzene, xylenes). In the case of a halogenated volatileorganic carbon compound (HVOC), PCE, gas/gas reaction of PCE toby-products of HCl, CO2 and H₂O accomplishes this. In the case ofpetroleum products like BTEX (benzene, toluene, ethylbenzene, andxylenes), the benzene entering the bubbles reacts to decompose to CO2and H2O.

Also, pseudo Criegee reactions with the substrate and ozone appeareffective in reducing saturated olefins like trichloro alkanes(1,1,1,-TCA), carbon tetrachloride (CCl₄), chloroform methyl chloride,and chlorobenzene, for instance.

Other contaminants that can be treated or removed include hydrocarbonsand, in particular, volatile chlorinated hydrocarbons such astetrachloroethene, trichloroethene, cisdichloroethene,transdichloroethene, 1-1-dichloroethene and vinyl chloride. Inparticular, other materials can also be removed including chloroalkanes,including 1,1,1 trichloroethane, 1,1, dichloroethane, methylenechloride, and chloroform. Also, aromatic ring compounds such asoxygenates such as O-xylene, P-xylene, naphthalene andmethyltetrabutylether (MTBE), ethyltetrabutylether, andtertiaryamyltylether can be treated.

Ozone is an effective oxidant used for the breakdown of organiccompounds in water treatment. The major problem in effectiveness is thatozone has a short lifetime. If ozone is mixed with sewage containingwater above ground, the half-life is normally minutes. Ozone reactsquantitatively with PCE to yield breakdown products of hydrochloricacid, carbon dioxide, and water.

To offset the short life span, the ozone is injected with directionalmicroporous diffusers, enhancing the selectiveness of action of theozone. By encapsulating the ozone in fine bubbles, the bubblespreferentially extract a vapor phase fraction of the volatile compoundsorganic compounds that the bubbles encounter. With this process, a vaporphase according to a partition governed by Henry's Law, of the volatileorganics are selectively pulled into the fine air-ozone bubbles. The gasthat enters a small bubble of volume (4πr3) increases until reaching anasymptotic value of saturation. The ozone in the bubbles attacks thevolatile organics, generally by a Criegee or Criegee-like reaction.

The following characteristics of the contaminants appear desirable forreaction:

Henry's Constant: 10⁻² to 10⁻⁵ m³ atm/mol

Solubility: 10 to 20,000 mg/l

Vapor pressure: 1 to 3000 mmhg

Saturation concentration: 5 to 9000 mg/kg

The production of microbubbles and selection of appropriate sizedistribution are selected for optimized gas exchange through highsurface area to volume ratio and long residence time within the area tobe treated.

Referring to FIG. 2, an illustrative installation of either treatmentexample of FIG. 1A or 1B or FIG. 8 (discussed below) is shown. In thisexample, multiple sparging apparatus (not numbered) here of a typedescribed in FIG. 1B, (although others could be used) are disposed overa site. In this example, “NEMA 4” (explosion proof) boxes enclosesolenoids and circuit boards 30 for remotely controlling the time andduration of the directional sparging. Such an arrangement can be used ingasoline spill areas, for example, where electrical circuits andsolenoids are isolated from contact with explosive vapors. By having aseparate circuit board in the well box, the well box can be placedanywhere along a pressurized main 37 for gas and liquid, as discussedbelow. Electrical current is supplied via a line 38 to operate thesolenoids and circuits 30. This simplifies installations that require alarge number of well installations since individual gas and liquidtubing from a master control 20 are not necessary to operate thewellhead.

Referring now to FIGS. 3A-3C, exemplary details of a directionalmicroporous diffuser 50 is shown. The directional microporous diffuser50 includes a holder member 52. The holder member 52 has a plurality ofcompartments 52 a formed by sidewalls 52 b of the holder member. Thecompartments correspond to the number of cylindrical tubes that will bein the microporous diffuser 50. In some embodiments, the sidewalls 52 bhave a flat surface upon which the cylindrical members rest. Here theholder member 52 is an elongated cross-like shape that will extend asubstantial length of the microporous diffuser 50. The microporousdiffuser 50 also includes here four (4) cylindrical members or tubes 54,each having a sidewall 54 a comprised of a large plurality ofmicropores. The four (4) cylindrical members or tubes 54 provide fourindependent diffusers that can be controlled to sequence emission offluids, e.g., gaseous ozone-air over e.g., 90 degree quadrants or thelike depending on the number of and arrangement of the cylindrical tubes54. Other configurations of fewer or more compartments and correspondingcylindrical (or other shaped) elongated members are possible.

As shown in FIG. 3B, one end 54 a of each of the cylindrical members 54has a pressure fitting 54 b threaded into threaded apertures (notshown), in the end 54 a of the cylindrical member to provide fluid inletports 59 whereas, as shown in FIG. 3C, the other end 54 b of thecylindrical members are sealed, via an end plug 60 or the like disposedin threaded (not shown) end portions 54 b of the cylindrical members 54.Other arrangements are possible, for instance caps having apertures canbe solvent welded to the ends of the cylindrical members instead ofproviding threads in the cylindrical members. Bands 56, e.g., nylonbands or straps are tightly strapped around the cylindrical members 54forcing them against the compartments 52 a in the holder member 52 andholding them in place. Other arrangements are possible.

The holder member 52 having the compartments 52 a within which thecylindrical tubes 54 are held tightly against the sidewalls 52 b of theholder member 52, tends to block portions of the tubes 54 from emittinggas in the form of bubbles, e.g., microbubbles, thus producing morepressure to force the bubbles from the unobstructed surfaces of thecylindrical tubes 54 to direct the pattern out over a quadrant and at ahigher operating pressure.

In some embodiments (FIG. 3D), the sidewalls 52 b have a contouredsurface that would generally follow contours of sidewalls 54 c of thecylindrical members 54. Optionally, to increase this tendency to blockgas from obstructed portions of the cylindrical tubes 54, thecompartments 52 a in the holder member 52 can be supplied with a weldingsolvent to solvent weld the cylindrical tubes 54 into the compartments52 a. Then, depending on operating pressures and the strength of thewelds the nylon straps 56 may be omitted.

The cylindrical tubes 54 have a porosity characteristic of slotwell-screen or preferably a microporosity characteristic of e.g., 200microns or less. In some embodiments the cylinders are slot well screensurrounded by a sand pack, e.g., 60 mesh sand pack. Slot sizes are setout below.

Slot Size Inches MM Microns 6 .006 .15 152 8 .008 .20 200 10 .010 .25250 12 .012 .30 304 15 .015 .37 375 20 .020 .50 500 25 .025 .62 625

In other embodiments, the cylinders can be constructed of porousmaterials having microscopic openings in sidewalls 54 c, as disclosedbelow. In other embodiments a mesh could be used. For example thecylinders of the diffuser can be comprised of a mesh having a mesh sizein a range of at least 40 mesh and in particular in a range of, e.g., 40to 200 mesh.

As shown in FIG. 3E, a borehole 61 can be provided through the holdermember 32, terminated at the end 54 c of the diffuser. The holder canhave weep holes 63 provided in the holder at the apex of the holder intothe borehole 61. A fitting (not shown) can be provided at the other endof the holder to accommodate connection to a second fluid, e.g., aliquid, as will be generally described in FIG. 8.

Referring now to FIGS. 4A-4C, examples of solenoid-controlled valve 30including inlet 31 and the outlet ports 32 a-32 d are shown (only ports32 a-32 c are used for valve 30 of FIG. 4C, which is used with threeinlets). Not shown in detail is electrical circuitry 35 that can be usedto remotely control the solenoids. When disposed in a wet soil, bubblesor microbubbles emerge from the quadrants in accordance with which oneof the inlet ports 58 of the directional microporous diffuser 50receives the fluid stream from the outlet ports 32 a-32 d of thesolenoid-controlled valve 30. While, the cylindrical member 54 isdisclosed as being cylindrical in shape, in general, the configurationcould have other shapes.

As mentioned, the cylindrical member 54 has a plurality of microscopicopenings constructed through sidewalls 54 c. The openings generally havea pore size matched to a surrounding ground formation so as to beeffective for inducing gas/gas reactions with introduction of themicrobubbles. Sidewalls of each of the cylindrical members can have apore diameter in a range of 1-200 microns, preferably 1-80 microns andmore preferably 0.1 to 20 microns, although 10 slot well screen could beused.

The combination of the inlet fittings 58 and end plug 60 seals thecylindrical tubes 54 permitting bubbles, or microbubbles, to escape onlyvia the porous construction of the sidewalls of the cylindrical tubes.

The use of plural cylindrical tubes 54 in the diffuser 50 together withthe solenoid valve 30 permits a gas stream from the central feed to bedirected through one, two, three or all four of the quadrants of thedirectional microporous diffuser 50. Thus, the pattern of the gas streamthat exits from the directional microporous diffuser can be sequenced.In general, using a single quadrant at a time permits the bubbles toexit the directional microporous diffuser and have a generallyelliptical shaped zone of influence in the surrounding soil formation.That is, by directing the gas stream from the feed line to one of thecylindrical tubes, the gas stream exits in the form of bubbles fromunobstructed surface of the tubes providing a zone of influence thatextends further in a direction perpendicular to the directionalmicroporous diffuser 50 than tangential to the directional microporousdiffuser 50. The treatment zone has a longer radius perpendicular to thesurface of the directional microporous diffuser than the treatment zonethat could be provided were the arrangement used with conventionalmicroporous diffuser.

The solenoid-controlled valve 30 can be controlled to rotate the patternof microbubbles emitted from the directional microporous diffuser 50 bypermitting microbubbles to exit from only a first quadrant, then only asecond quadrant, and so forth. The control can be automated or manual.The directional microporous diffuser 50 allows fewer wells and spargingarrangements 10 to be constructed on a site for a given spargingarrangement capacity by directing all of the capacity of the pumps andso forth into a single quadrant of a directional microporous diffuser atany one time. The directional microporous diffuser 50 can also be usedto direct treatment towards especially high concentrations ofcontaminants while minimizing treatment materials in areas of lowercontaminant concentrations. Once a first region is treated, the solenoidcan be activated to close the outlet that feeds the first quadrant thattreated the first region and open a second outlet of the solenoid tofeed a second, different quadrant and treat a second different region.

The arrangement can also be used to treat contaminants that exist underroad beds, buildings or other areas in which it is not feasible todirectly drill wells. Since the directional microporous diffuser 50 candirect all of the fluid supplied to the solenoid controlled value to oneof the cylindrical tubes 54 and though less than the entire surface areaof the one cylindrical tube, the effective radius of influence isconcomitantly greater than prior approaches for a given pressure andflow rate of fluid.

Referring now to FIGS. 5A-5D, exemplary details of an alternative,directional microporous diffuser 70 that allows adjusting of a shape ofa bubble pattern is shown. The directional microporous diffuser 70includes a holder member 72. The holder member 72 has a plurality ofcompartments 72 a formed by sidewalls 72 b of the holder member and hasa plurality of attachment surfaces 72 c disposed between adjacentcompartments 72 a. The compartments 72 a correspond to the number ofcylindrical tubes that will be in the microporous diffuser 50 and theattachment surfaces 72 a provide attachment regions for holder pieces74. Each of the holder pieces has a base 74 a that attaches to theattachment surface 72 c of the holder 72, an opposing outer surface 74b, and sidewalls 74 c having a contoured surface that would generallyfollow contours of cylindrical members 78. A pair of sidewalls 74 c fromneighboring holder pieces 74 and the compartment 72 a disposed betweenthe neighboring holder pieces 74 provides a composite compartment thatholds a cylindrical tube 78.

Bore holes 79 are disposed through the holder pieces 74 aligned withtapped screw holes in holder member 74 for screws (not labeled) toattach the holder pieces 74 to the holder 72. Other fastening could beused. Here the holder member 72 is an elongated cross-like shape thatwill extend a substantial length of the microporous diffuser 70.

The microporous diffuser 70 also includes here four (4) cylindricalmembers or tubes 78, each having a sidewall comprised of a largeplurality of micropores. The four (4) cylindrical members or tubes 78provide four, independent diffusers that can be controlled to sequenceemission of fluids, e.g., gaseous ozone-air over e.g., 90 degreequadrants or the like depending on the number of and arrangement of thecylindrical tubes 78. Top and sides views of the directional microporousdiffuser are illustrated in FIGS. 5B and 5C.

As shown in FIG. 5B, one end 78 a of the cylindrical members has apressure fitting 84, threaded into threaded apertures (not shown), inthe end of the cylindrical member 78 to provide fluid inlet ports 88,whereas, the other end 78 b (FIG. 5C) of the cylindrical members 78 aresealed, via an end plug 85 or the like. Other arrangements, e.g.,welding are possible.

The holder member 72 having the compartments 72 a within which thecylindrical tubes 78 are held tightly against the sidewalls 72 b of theholder member 72, tends to block portions of the tubes from emitting gasin the form of bubbles, e.g., microbubbles, thus producing more pressureto force the bubbles from the unobstructed surfaces of the cylindricaltubes 78 to direct the pattern out over a quadrant and at a higheroperating pressure. Optionally, to increase this tendency to block gasfrom obstructed portions of the cylindrical tubes 78, the compartments72 a in the holder member 72 can be supplied with a welding solvent tosolvent weld the cylindrical tubes 78 into the compartments 72 a.

As above, the cylindrical members 74 have a porosity characteristic of10 slot well screen or a microporosity characteristic of e.g., 200microns or less. When disposed in a wet soil, bubbles or microbubblesemerge from the quadrants in accordance with which one of the inletports 88 of the directional microporous diffuser 70 receives the fluidstream from the outlet ports 32 a-32 d of the solenoid-controlled valve30 (FIG. 4).

While the cylindrical member 78 is disclosed as being cylindrical inshape, in general, the configuration could have other shapes.

As mentioned above for cylindrical member 54 (FIGS. 3A-3C) cylindricalmember 78 has a plurality of microscopic openings constructed throughsidewalls 78 a. The openings generally have a pore size matched to asurrounding ground formation so as to be effective for inducing gas/gasreactions with introduction of the microbubbles. Sidewalls of each ofthe cylindrical members can have a pore diameter in a range of 1-200microns, preferably 1-80 microns and more preferably 0.1-20 microns,although 10 slot well screen could be used.

The combination of the inlet ports 88 and end plug 85 seals thecylindrical tubes 78 permitting bubbles, or microbubbles, to escape onlyvia the porous construction of the sidewalls of the cylindrical tubes.

The use of plural cylindrical tubes 78 in the diffuser 70 together withthe solenoid valve 30 permits a gas stream from the central feed to bedirected through one, two, three or all four of the quadrants of thedirectional microporous diffuser 70. Also, as mentioned, the holderpieces 74 allow various shaped patterns, e.g., an ellipsoidal patternwhen the gas stream exits from all four cylindrical members 78 or aneffectively ellipsoidal pattern, when the directional microporousdiffuser 70 is sequenced. In general, using a single quadrant at a timepermits the bubbles to exit the directional microporous diffuser andhave a generally elliptical shaped zone of influence in the surroundingsoil formation. That is, by directing all of the gas stream from thefeed line to one of the cylindrical tubes, the gas stream exits in theform of bubbles from unobstructed surface of the tubes providing a zoneof influence that extends further in a direction perpendicular to thedirectional microporous diffuser 50 than tangential to the sidewalls ofthe directional microporous diffuser 50. The treatment zone has a longerradius perpendicular to the surface of the directional microporousdiffuser than the treatment zone that could be provided were thearrangement used with conventional microporous diffuser.

The solenoid-controlled valve 30 can be controlled to sequence thepattern of microbubbles emitted from the directional microporousdiffuser 70 by permitting microbubbles to exit from only a firstquadrant, then only a second quadrant, and so forth. The control can beautomated or manual. The directional microporous diffuser 50 allowsfewer wells and sparging arrangements 10 to be constructed on a site fora given sparging arrangement capacity by directing all of the capacityof the pumps and so forth into a single quadrant of a directionalmicroporous diffuser 70 at any one time. The directional microporousdiffuser 70 can also be used to direct treatment towards especially highconcentrations of contaminants while minimizing treatment materials inareas of lower contaminant concentrations. Once a first region istreated, the solenoid can be activated to close the outlet that feedsthe first quadrant that treated the first region and open a secondoutlet of the solenoid to feed a second, different quadrant and treat asecond different region.

As above with diffuser 50, the diffuser 70 can also be used to treatcontaminants that exist under road beds, buildings or other areas inwhich it is not feasible to directly drill wells. Since the directionalmicroporous diffuser 50 can direct all of the fluid supplied to thesolenoid controlled value to one of the cylindrical tubes 54 and thoughless than the entire surface area of the one cylindrical tube, theeffective radius of influence is concomitantly greater than priorapproaches for a given pressure and flow rate of fluid. Moreover, unlikediffuser 50, diffuser 70 can further shape the beam of fluid that exitsfrom any particular cylindrical member 78 by judicious selection of thewidths, e.g., W1 and W2 of the holder pieces 74, as shown in FIG. 5D.

Referring now to FIGS. 6A, 6B details of sidewalls of the directionalmicroporous diffusers 50, 70 are shown. FIG. 6A shows that sidewalls ofthe members can be constructed from a metal or a plastic support layer91 having large (as shown) or fine perforations 91 a over which isdisposed a layer of a sintered i.e., heat fused microscopic particles ofplastic. The plastic can be any hydrophobic material such aspolyvinylchloride, polypropylene, polyethylene, polyvinylidene, (PVDF),polytetrafluoroethylene, high-density polyethylene (HDPE) and ABS. Thesupport layer 91 can have fine or coarse openings and can be of othertypes of materials. Other materials are possible such as porousstainless steel and so forth.

FIG. 6B shows an alternative arrangement 94 in which sidewalls of themembers are formed of a sintered i.e., heat fused microscopic particlesof plastic. The plastic can be any hydrophobic material such aspolyvinylchloride, polypropylene, polyethylene, polyvinylidene, (PVDF),polytetrafluoroethylene, high-density polyethylene (HDPE) andalkylbenzylsulfonate (ABS).

The fittings (e.g., the inlets in FIGS. 3A-3D, 5A-5C) can be threadedand are attached to the inlet cap members by epoxy, heat fusion, solventor welding with heat treatment to remove volatile solvents or otherapproaches. Standard threading can be used, for example, NPT (nationalpipe thread) or box thread e.g., (F480). The fittings are securelyattached to the directional microporous diffusers in a manner thatinsures that the directional microporous diffusers can handle pressuresthat are encountered with injecting of the air/ozone.

Referring now to FIGS. 7A-7C, an alternate embodiment 70′ of thedirectional microporous diffuser 70 is shown. The alternative,directional microporous diffuser 70′ allows adjusting of a shape of abubble pattern as with 70 (FIGS. 5A-5C) and allows a second fluid, e.g.,a liquid to be dispersed along with the first fluid from the cylindricaltubes 74. The directional microporous diffuser 70′ includes a holdermember 72′, similar in construction to holder member 72 discussed above.Here the holder member 72′ has, in addition to the features disclosedfrom holder member 72, a borehole 73 through the length of the holdermember, with one end of the borehole 73 having a threaded region toreceive a fitting 73 a. The other end of the borehole 73 can be pluggedor terminated inside of the holder member 72. In other respects, themicroporous diffuser 70′ is similar or the same in construction asmicroporous diffuser 70. The holder pieces 74′ are similar inconstruction to those 74 of diffuser 70 (FIGS. 5A-5C); however, theyinclude one or more liquid outlet ports 75, e.g., apertures through thethickness of the holder pieces and through the holder member terminatingin the borehole 73, such that liquid or another fluid that is fedthrough the borehole can exit from the diffuser 70′.

As above with diffuser 50 and diffuser 70, the diffuser 70′ can also beused to treat contaminants that exist under road beds, buildings orother areas in which it is not feasible to directly drill wells. As withdiffuser 70, diffuser 70′ can further shape the beam of fluid that exitsfrom any particular cylindrical member 78 by judicious selection of thewidths “W” of the holder pieces 74.

The gas stream that exits from cylindrical members 78 mixes with, e.g.,liquid from the outlets to coat microbubbles with a liquid coating of,e.g., water or hydrogen peroxide or a hydro peroxide. Other known liquidde-contaminant agents could be used. In general, using a single quadrantat a time permits the coated microbubbles to exit the directionalmicroporous diffuser 70 over the sidewall surface of a single quadrant.The coated microbubbles cover a generally elliptical shaped zone ofinfluence in the surrounding soil formation, as discussed above fordirectional microporous diffuser 50 and 70.

Referring to FIG. 8, an example of a sparging arrangement 120 using thedirectional microporous diffuser 70′ is shown. The sparging arrangement120 includes a source 123 (of liquid and catalysts, and/or nutrients)and a pump 122 coupled to a check valve 125 and a secondsolenoid-controlled valve 130. The second solenoid-controlled valve 130has an outlet coupled to liquid feed line 133 that is coupled to inletport 73 a of the directional microporous diffuser 70′. The directionalmicroporous diffuser 70′ receives liquid, catalysts, and/or nutrients,which mixes in the directional microporous diffuser 70′ with the gaseousstream provided via feed lines 33 to provide an emulsion of microbubblesand liquid, or catalysts etc. and preferably coated microbubbles and soforth, as in the patents mentioned above, e.g., U.S. Pat. No. 6,582,611or 6,436,285 for instance. Otherwise, the arrangement 120, as shown inFIG. 8, is analogous to the arrangements 10, 100 shown in FIG. 1A or 1Bbut for the addition of the pump 122, source 123, check valve 125, feedline 133 and the second solenoid-controlled valve 130. The controlarrangement 35 is shown controlling both solenoid-controlled valves 30and 130.

Referring now to FIG. 9A, another construction 50′ for the directionalmicroporous diffuser 50 is shown. The directional microporous diffuser50′ includes a holder member 52′. The holder member 52′ has fourcompartments 52 a′ formed as two pairs of adjacent compartments onopposing sidewalls 52 b′ 52 b″ of the holder member 52′. Thecompartments 52 a′ correspond to the number of cylindrical tubes thatwill be in the microporous diffuser 50′. A pair of holder pieces 54 isused to secure the cylindrical tubes 56 to the holder 52′.

Other configurations of fewer or more compartments and correspondingcylindrical (or other shaped) elongated members are possible. Otheralternative arrangements are shown in FIGS. 9B and 9C.

Referring now to FIG. 9B, another construction 50″ for the directionalmicroporous diffuser 50 includes a holder member 52″. The holder member52″ has five compartments 52 a″. The compartments 52 a″ correspond tothe number of cylindrical tubes that will be in the microporous diffuser50″. Five holder pieces 54″ are used to secure the cylindrical tubes 56to the holder 52″.

Referring now to FIG. 9C, another construction 50′″ for the directionalmicroporous diffuser 50 includes a holder member 52′″. The holder member52′″ has three compartments 52 a′″. The compartments 52 a′″ correspondto the number of cylindrical tubes that will be in the microporousdiffuser 50′″. Three holder pieces 54″ are used to secure thecylindrical tubes 56 to the holder 52′″.

Similar arrangements with a borehole as in FIGS. 7A-7C can be providedfor the constructions 50′-50′″.

A number of embodiments of the invention have been described.Nevertheless, it will be understood that various modifications may bemade without departing from the spirit and scope of the invention.

1. A method comprises: delivering plural streams of a fluid to pluralinlets of a diffuser comprised of plural hollow elongated members eachhaving porous sidewalls; and emitting at least one stream of the fluidinto a soil formation through at least one of the plural hollow,elongated members.
 2. The method of claim 1 wherein the inlets arecoupled to one end of the plural hollow members with opposing ends ofthe members being sealed.
 3. The method of claim 2 further comprising:sequencing fluids to the inlets to provide the plural streams indifferent sequences.
 4. The method of claim 2 further comprising:controlling a solenoid controlled, multi-port valve to sequencing fluidsto the inlets to provide the plural streams in different sequences. 5.The method of claim 2 wherein the diffuser is a microporous diffuser andcomprises a holder member supporting the plural hollow, elongatedmembers in plural compartments of the holder member.
 6. The method ofclaim 1 wherein the elongated members are comprised of well screen. 7.The method of claim 6 further comprising emitting microbubbles having abubble diameter of less than 200 microns.
 8. The method of claim 2further comprising driving the diffuser into the ground.
 9. The methodof claim 2 further comprising disposing the diffuser in a well.
 10. Themethod of claim 2 wherein the diffuser emits microbubbles having a sizein a range of 1 to 200 microns.
 11. The method of claim 1 wherein thediffuser is comprised of 10 slot well-screen.
 12. The method of claim 1wherein the diffuser is comprised of a mesh having a mesh size in arange of 40 to 200 mesh.
 13. An apparatus comprising: a plurality ofdirectional diffusers arranged in a spaced arrangement to treat a site;a trunk line that delivers a fluid to the plurality of directionaldiffusers; a plurality of multi-port distribution valves in proximity toinlet ports of the directional diffusers; and for each of the multi-portdistribution values, a plurality of feed lines coupled from themulti-port distribution value to inlets on the directional diffusers.14. The apparatus of claim 13 further comprising: an ozone generatorcoupled to the trunk line and wherein the first fluid comprises ozone.15. The apparatus of claim 13 further comprising: an air compressorcoupled to the trunk line an ozone generator coupled to the trunk lineand wherein the first fluid comprises air-ozone.
 16. The apparatus ofclaim 13 wherein at least one of the directional diffusers has an inletfor receiving a flow of a second fluid.
 17. The apparatus of claim 13wherein at least one of the directional diffusers comprises: an inletfor receiving a flow of a second fluid, that is surrounded by aplurality of inlets that receive flows of the first fluid.
 18. Theapparatus of claim 17 wherein the diffuser is 10 slot well-screen, andthe apparatus further comprises: a source of air-ozone as the firstfluid; and a source of a peroxide as the second fluid.
 19. The apparatusof claim 13 wherein the directional diffusers are microporousdirectional diffusers and the apparatus further comprises: a source ofair-ozone as the first fluid; and a source of a peroxide as the secondfluid.
 20. The apparatus of claim 19 wherein the directional diffusercomprises: a pointed member disposed on a portion of the directionaldiffuser to allow the directional diffuser to be driven into the ground.21. The apparatus of claim 13 wherein the directional diffuser ismicroporous having a pore size in a range of 0.1 to 200 microns.
 22. Theapparatus of claim 13 wherein the directional diffuser is comprised of amesh having a mesh size of at least 40 mesh.
 23. The apparatus of claim13 wherein the directional diffuser is comprised of a mesh having a meshsize in a range of 40 to 200 mesh.
 24. Apparatus comprises: a holdermember having plural compartments; plural hollow, elongated membershaving porous sidewalls, the plural hollow, elongated members supportedin the plural compartments of the holder member with each hollow,elongated member including: an inlet port at a first end of theelongated member; and a second end of the elongated member being sealed.25. The apparatus of claim 24 wherein the holder member is elongated,with sidewalls of the plural hollow, elongated members having a porositycharacteristic of 10 slot well-screen or less.
 26. The apparatus ofclaim 25 wherein sidewalls of the plural elongated members have aporosity characteristic of less than 200 microns.
 27. The apparatus ofclaim 24 wherein the plural hollow, elongated members are cylinders. 28.The apparatus of claim 24 wherein the plural, hollow elongated membersare comprised of a metal or a plastic.
 29. The apparatus of claim 24wherein the plural, hollow elongated members are comprised of a plasticthat is a hydrophobic material.
 30. The apparatus of claim 24 whereinplural, hollow elongated members are comprised of sintered, fusedmicroscopic particles of plastic.
 31. The apparatus of claim 24 whereinthe compartments have walls that have a curvature that corresponds to acurvature of the plural, hollow elongated members.
 32. The apparatus ofclaim 24 further comprising: at least one band that is disposed aboutthe plural members to hold the plural members in the compartments of theholder member.
 33. The apparatus of claim 24 wherein the compartmentsare arranged in quadrants.
 34. The apparatus of claim 24 wherein theholder member has a borehole through a length of the holder member. 35.The apparatus of claim 34 further comprising: an inlet attached to theholder member to feed fluid into the borehole in the holder member. 36.A microporous diffuser comprises: a holder member having pluralcompartments, each compartment having a generally partially circularsidewall; plural hollow, cylindrical tubes having porous sidewalls, theplural hollow, cylindrical tubes supported in the plural compartments ofthe holder member with each hollow, cylindrical tubes including: aninlet port at a first end of the cylindrical tubes with a second end ofthe cylindrical tube being sealed.
 37. The microporous diffuser of claim36 wherein the holder member is elongated, and with the cylindricaltubes having a porosity characteristic of 10 slot well-screen or less.38. The microporous diffuser of claim 36 wherein sidewalls of thecylindrical tubes have a porosity characteristic of less than 200microns.
 39. The microporous diffuser of claim 36 wherein cylindricaltubes are comprised of a metal or a plastic.
 40. The microporousdiffuser of claim 36 further comprising: at least one member disposed tohold the plural cylindrical tubes in the compartments of the holdermember.
 41. The microporous diffuser of claim 36 wherein thecompartments are arranged in quadrants and wherein there are fourcylindrical tubes.